Frustrated over the stalemate in funding mass transit, labor unions representing CTA bus drivers and train operators have approved a one-day job action, threatening to throw a roadblock into rush-hour commutes as early as Monday morning.

Union leaders said the planned walk-off aims to send the strongest message yet to the governor and lawmakers in Springfield that the deadlock must end over funding the CTA, Metra and Pace .

But similar threats have fizzled in the past and could unravel this time, too.

Indeed, hours after deciding to go ahead with the 24-hour job action beginning at 8 p.m. Sunday, officials from more than a dozen transit unions met again Thursday night to possibly delay or cancel the walkout. CTA union members authorized a walkout two weeks ago.

Bryant Alexander, second vice president of Local 308, representing CTA rail workers in the Amalgamated Transit Union, said the chances of "avoiding a job action do not look good."

"The CTA realizes the impact of what we could do," Alexander said. "But if the politicians keep screwing us around, we have to show them how it would look every day without mass transit."

If successful, the shutdown of much or all CTA bus and rail service for 24 hours would paralyze downtown Chicago and overwhelm transportation across the region. The CTA serves 40 suburbs.

But CTA President Ron Huberman said any job action at the CTA would be considered illegal.

Under Illinois law, CTA employees and other transportation workers are prohibited from striking because they provide an essential service.

But union members contend that employees who fail to work for a day are not strikers and that an unspecified job action does not violate state law or union contracts with the transit agencies.

The CTA employs more than 10,000 union members. The ultimate goal is to halt all CTA, Metra and Pace operations to demonstrate the need for more transit funding and to restore balance to union pension funds and health-care plans. But such a widespread walkout would require the cooperation of 19 unions at the three transit properties in the Regional Transportation Authority system.

"We want to make sure the public is aware of our job action ahead of time," said Rick Harris, president of ATU Local 308. "We don't want to hurt the public."

"But we are fed up with the state funding situation in the legislature and the layoffs and service cuts in January."

Next month the CTA plans to lay off about 2,400 workers, eliminate 81 bus routes and raise fares unless new subsidies are provided to close a projected $158 million budget deficit in 2008.

In addition, the CTA's employee pension fund is underfunded and deteriorating fast. It is projected to go broke in 2012. In addition, health benefits to CTA retirees could be cut off next summer due to under-funding.

Pace, the suburban bus agency, is also set to cut all evening service and weekday and/or weekend service on 102 routes and 65 Metra feeder and shuttle routes in January.

Metra has approved a 10 percent fare increase starting in February and additional 10 percent hikes in 2009 and 2010.

Legislative leaders and Gov. Rod Blagojevich are at odds over how to raise new revenue for mass transit and pay for a new statewide capital improvement program.

One funding proposal still on the table -- increasing the sales tax in the six-county RTA region -- also would include reforms in the CTA pension and retiree health-care funds. The CTA would save $11 million a month under the reforms.

It is unlikely any of Metra's approximately 2,000 union employees would take part in a walkout, said Judy Pardonnet, spokeswoman for the commuter railroad. Job actions are prohibited under the federal Railway Labor Act.

Rick Radek, vice president of the Brotherhood of Locomotive Engineers and Trainmen unit representing Metra engineers, said the union will not engage in a job action.

"We certainly have sympathy for the people at the CTA, and we are in Springfield lobbying to get the money for the CTA and Metra," Radek said. "But I think it would be irresponsible on our part to engage in some sort of job action."

Pace spokesman Patrick Wilmot said Pace had no indication whether the suburban bus agency's union workers would participate in the job action.